Low-speed shimmy

[HondaJon_imp]

Just curious if anyone else has experienced any low speed shimmy on their CB? I only have about 100 miles in so far (damn rain) and noticed it today while riding. It's not too bad, but I don't get any on the XR 650L at all. I check the tire pressure (Dead on at 36 and 42 psi) and snugged all of the front end bolts. I didn't hit the steering head though.
I did noticed that the front tire does not have any wheel weights on it though. Just wondering if this is a characteristic of the bike before I take her back to the dealer for a check.
Thanks

 

[Randy B]

Take it in. I'm almost at 5000 miles and it's dead smooth.

 

[the Ferret]

No shimmy I have noticed

 

[Deanohh_imp]

Shouldn't do that.... Take it in soon.

 

[thumper_imp]

None here. Have it checked out.

 

[vfrpaul98_imp]

slowing down? constant slow speed? do you have both hands on the handlebar grips? it is not uncommon for some machines to shake their heads when slowing down with your hands not holding the handlebar grips. ask your dealer to check front fork spring preload. make sure your fork tubes are installed in the steering stems at the proper height.if the front ride height has been lowered by slideing the fork tubes up in the stems this might cause a problem if the rear is not lowered at the same time.
Paul.

 

[Guth_imp]

New bike, under warranty, shouldn't be exhibiting such behavior. I'd take it back to the dealer and have them make it right.

 

[_imp]

New bike, under warranty, shouldn't be exhibiting such behavior. I'd take it back to the dealer and have them make it right.

It is probably the stock front tire. They don't make 'em like that anymore, except they do, for this bike. It has the dreaded "center groove" which will catch any irregularities in the pavement and give you a wiggle. It is especially bad where there are rain grooves. I noticed this on mine and looked at the tire realizing what the problem was. However you should still take it in because it's a safety issue. The steering head bearings may not have been installed correctly.
One other thing that was common with bikes of this era is a bit of headshake if you take your hands off the bars, especially whilst decelerating through 45 mph. There were a few magazine articles about this trait back in day. I had a couple of bikes that did this.

 

[HondaJon_imp]

Well it finally stopped raining here, so I took her out for a better test and this is what I found;

The shimmy is most pronounced while decelerating from 50-40 (Just like V452CB1100 noted) with my hands off of the bars.
Page 12-15 of the Honda service manual states "For optimum balance, the tire balance mark must be located next to the valve stem". Mine is not. (See pic)

I'm hoping it's just a simple tire balance issue, all of my other Honda bikes have been smooth as glass. Will be taking her in next week and will let you all know what the outcome was.

Thanks for the input.

 

[Deanohh_imp]

But you have the dot on the rim where they have balanced the wheel. Indicates the optimal spot for the tire mark.

 

[the Ferret]

Very common

http://www.google.com/#sclient=tablet-gw...24&bih=672

Or just google " why motorcycles shimmy" and check out how many motorcycle forums deal with this question. Manufaturers will tell you not to let go of the bars.

 

[HondaJon_imp]

I'm sure Ferret, problem is I feel it when hold on to them, only let go to see what was going on.

My guess is that the tire is a tad out of balance. No wheel weights at all on the front.

 

[the Ferret]

I dont feel it in my CB so you may be onto something with the balance question.

My 750 Nighthawk had one you could feel while holding onto the bars, which after checking everything could not be cured, until I added a Superbrace fork brace.

 

[FUZZY_imp]

Last H-D had it while slowing, hands off bars. Mine was a front tire problem. It was the factory new tire. Some were neck bearing set up. H-D replaced my tire & never had it again.

 

[Deanohh_imp]

Even if thought I knew the cause, would stick with only my concern for the symptom, and not try to steer the mechanics by guessing what the cause is. Its their job to check everything, analyze and determine the repair.

 

[The Spaceman_imp]

The VStrom I came from is notorious for headshake on decel, especially with your hands off the bars. If everything is perfect on them; balance, alignment, suspension, etc., they won't do it. But mine always did. The CB, however, does not. Yours probably needs a minor adjustment.

 

[Lord Popgun]

Well mine is perfect (Whewww) Could it be tire pressure?

Could some of the knowledgeable speak to the affects of low or high pressure on handling?

 

[_imp]

Well mine is perfect (Whewww) Could it be tire pressure?

Could some of the knowledgeable speak to the affects of low or high pressure on handling?

Low tire pressure could cause this. Mine came with 32/36 from the dealer. WRONG.

Low = sluggish and unstable
High = harsh and uncompliant

 

[HondaJon_imp]

Checked the pressure again today, she is dead on spec; 36 psi in the front and 42 psi in the rear. I'm 99% sure it's just a balance/bad tire issue. My bike was delivered to me with 0 miles, so it was never ridden by the dealer to feel something like this out.

My dealer was closed today due to an extended 4th of July vacation so I couldn't' run her in.

Will let all of you know what I find out. It is good to hear that no one else has had an issue. Honda's build quality is top notch, so I'm really not worried.

My Hayabusa felt funny after a few thousand miles (I bought her used) A new set of Metzelers fixed everything.

 

[thumper_imp]

HondaJon--Don't overly fret the no wheel weight issue. I change quite a few tires during the year (multiple bikes, instructor), and every now and then a tire will balance w/o any weights. Not often, but it does happen time to time.